This invention relates to cleaning apparatus for video cassette players, and particularly to players having a configuration in which the capstan extends into the cassette-receiving cavity. The focus of this invention is on means for cleaning the capstan shaft.
Most consumers are familiar with two types of video cassette formats--the "BETAMAX" and the "VHS." There are a number of differences in both the configuration and operation of the equipment for these two formats. One of these differecces is the location of the capstan. i.e. the rotating shaft in the player/recorder which engages the tape of a cassette during operation and regulates the tape speed. In the BETAMAX format, the capstan is positioned a few inches forward of the cassette-receiving cavity. During operation of the player/recorder, the video tape is drawn toward the capstan by a series of rollers located on a wheel which moves them from a position within the perimeter of the cassette (and inside the tape loop) to a position several inches forward of the cassette boundary. This draws the tape out from the cassette and extends it around an irregular path contacting all of the sensing and regulating components of the system including the capstan. In the VHS format, the capstan is located within the cassette-receiving cavity itself, and positioned to enter an indentation along the exposed-tape edge of the cassette housing when the cassette is inserted in the cavity. The capstan is thus behind and either in contact with or near the tape at all times, despite the fact that, as in the BETAMAX format, the tape is drawn out of the cassette by moving rollers during operation.
This difference in capstan location has a bearing on the operation of cleaning devices. As maufacturers frequently remind the consumer, the system components contacting the video tape should be cleaned periodically if the system is used with any frequency. To this end, cleaning devices in the shape of video cassettes are sold or rented, which are operated simply by insertion of the device into the machine and activation of the "PLAY" mode in the same manner as a video cassette. A claaning ribbon in such a device takes the place of the video tape, and is accordingly manipulated by the system in the same manner as the video tape to contact the system components. These devices are particularly appealing due to their ease of use and convenient shape and size.
Among the various components of the system, the capstan is critical in terms of cleaning since the tape is forced tightly against it by a pinch roller, and it is the one component that is externally driven to control the tape speed. The capstan in a BETAMAX system, or any system in which the capstan is removed from the cassette cavity, must be cleaned by the cleaning ribbon in the same manner as the other components (audio head, video head. erase head, etc.). In the VHS system, however, a capstan cleaning head may be positioned on the cleaner housing itself. This permits the use of a pad of absorbent material wetted with a cleaning solution pressing against the rotating capstan, rather than a cleaning ribbon, and hence a more rigorous cleaning.
Since the pad is stationary, it collects debris from the capstan shaft in a relatively narrow area on the pad surface. After only a small number of uses, this area becomes contaminated to the extent that effective cleaning is impossible. For this reason, cleaning devices have been designed with replaceable pads. Unfortunately, extra tools or a high degree of manual dexterity and a complicated sequence of steps are frequently required to effect removal and replacement of the pad.